I have both installed for a few years now (Debian on Desktop and Server, Ubuntu on Laptop). First of all every article mentioning something like "I switched recently and everything is fine" just gives me a little sad smile. Yes - every Distro after a fresh install will usually work pretty well by now. Problems tend to show after using it daily for a few months.
My experience is that new Ubuntu versions tend to mess up things often, but I also notice that stuff gets fixed rather often within days. And otherwise one can find lots of workarounds and help thanks to a large and active community. That includes a workaround to disable the internet search for everything in the dash for example.
Debian is fantastic on the server and updates just worked there for me so far. On the Desktop on the other hand the situation is a lot more problematic. Old desktop software is generally just worse than newer one. And software on Debian tends to be outdated so much that I run constantly into old bugs which are solved often for months or even years in current application versions, but not yet in Debian. Pretty much every Desktop application where you want newer versions is simply not available. And applications generally won't get updated between release cycles because that's just not what stable does (except for security fixes). Even finding a browser which simply runs on all websites tends to be a constant pain. So you start trying to work with backports, custom compiled versions, installing packages build for Ubuntu and whatever you can do to get applications you need running - which can cause more and more problems in your system and you will get less and less help from the Debian community because those are (understandably) not "their" packages.
When you bring up those problems the community often recommends using "testing" or "unstable" and while those generally have newer apps they are still mostly outdated. Also while most updates on testing and unstable work most of the time they did mess up my system once in a while on updates so badly that I tended to only update on weekends after a while to have enough time to fix my system before I had to work with it again for the week (which is why I switched to only using stable now for the last 3 versions, maybe unstable/testing have gotten better since then, I can't tell about that).
I still love Debian for it's policy and community. And because I can fix problems often myself (or with the help of the community) and hope that my feedback is useful once in a while and will improve it in the long term I still continue to use it despite the pain. But unfortunately I can't recommend any Debian version right now for the Desktop for people without good Unix knowledge unless they work only with a very restricted set of desktop applications (so might be fine for company desktops where users are not allowed to install anything anyway).